Machine for truing lens-grinding laps



Jan. 8 1924. 1 1,480,438

I J. J. GUILFQYLE ET AL.

MACHINE FOR TRUING LENS GRINDING LAPS Filed June 15 1922 3 Sheets-Sheetl J I v i i (mantel-s Jan. 8, 1924. 1,4801438 V J. J. GUIL FQYLE ET ALMACHINE FOR TRUING I JENS GRINDING LAPS Filed June 15, 1922 '5Sheets-Sheet 8,

$1 Hue nto-as ua/nwa d ya Za Zr eeiar z 0-5 Bela/ambit lzerhz PatentedJan. 8, 1924.

UNITED STATES PATENT OFFICE.

JOHN J. GUILFOYLE, FREDERICK w. WILKES, AND BENJAMIN E. BEIER'TON, 0F

BIRMINGHAM, ALABAMA.

MACHINE FOR TRUIN'G Application filed June 15,

To all whom it may concern:

Be it known that we, JoHN J. GUILFOYLE, FREDERICK WV. WILKES, andBENJAMIN E. BRIERTON, citizens of the United States, residing atBirmingham, in the county of Jefferson and State of Alabama, haveinvented new and useful Improvements in Machines for TruingLens-Grinding Laps, of which the following is a specification.

The present invention relates to the initial truingor re-truingoflapsand similar tools having curved surfaces, and more particu larly tothose of the kind used in grinding ophthalmic 01' other lenses.

Lenses, and particularly ophthalmic lenses are usually produced bygrinding, using tools, commonly called laps, which are composedgenerally of metal having surfaces of various curvatures conforming withthe respective curvatures of the surfaces to be given the finishedlenses. These laps not only require the initial production of truesurfaces thereon corresponding accurately with the surfaces of thelenses to be produced, but they become untrue after use, owing to theuneven wear thereon, and hence they become unfit for further use, unlessthey can be re-trued accurately and economically.

The primary object of this invention is to v provide a machine which iscapable ofinexpensively and accurately truing or re-truing laps of thischaracter and similar tools havving curved surfaces, the machineembodying means for accommodating it to the various curvatures of thesurfaces of the laps. both convex and concave, and it also embodiesmeans for accommodating it to laps having surfaces of different radii ondifferent meridians, or to a surface having a plane or rectilinearsurface on a meridian thereof. The machine is thus rendered capable oftruing all of the great variety of laps ordinarily used in the grindingof ophthalmic lenses, including those having spherical,

cylindrical and toric surfaces, both convex and concave.

To these and other ends, the invention consists in certain improvementsand combinations and arrangements of parts, all as will be hereinaftermore fully described, the features of novelty being pointed'outparticularly in the claims at the end of'the speci-' fication. I

LENS-GRINDING Lars.

1922. Serial No. 568,653.

In the accompanying drawings Figure 1 is a top plan view of a lap truingmachine constructed in accordance with the preferred embodiment of theinvention;

Figure 2 represents an elevation of the machine shown in Figure 1,looking from below in that figure;

Figure 3 is a collective view showing in detail and in detached relationthe parts composing the too-l holder;

Figure 4 is a detail view, partly in section, illustrating the toolholder in operative relation with the lap holder;

Figures 5 and 6 are detail views of driving elements of the machine;

Figure 7 is a detail view, partly in section, showing one of theeccentric driving members;

Figure 8 is a detail view, partly in section, of the means for guidingthe tool holder during its movements in one direction; and

Figure 9 is an elevation of the guiding means shown in Figure 8.

Similar parts are designated by the same reference characters in theseveral views.

The present invention provides a machine which is capable of usegenerally for forming surfaces of various kinds on differentarticles,'although it is particularly adapted for use in the truing andre-trui-ng of the surfaces of lens grinding laps. The preferredembodiment of the invention is shown in the accompanying drawings andwill be hereinafter described in detail. It is'to be understood,however, that the invention is not restricted to the preciseconstruction shown, but that equivalent constructions are contemplatedand these -will be included within the scope of the claims.

In the present instance, the machine comprises a suitable base 1 whichmay be in the form'xof a table and which serves as a support for thevarious operative parts of the machine. The machine comprises a driv=ing shaft 2 having a pulley 3 or other suitable means for receivingpower from a suit able source, this shaft being journall'ed in bearings4 on the'base and havin a crank 5 fixed to one end and provided wit acrank pin 6 and having a worm 7 s'plined on and is driven from the shaft2 by a worm wheel.

10 which is fixed on the shaft 8 and meshes with the worm 7 on the shaft2. During the operation of the machine, the shaft 2 has a to-and-froendwise movement in its bearings 4 and in order to enable the worm 7 tomaintain a correct operative relation with the worm wheel 10,notwithstanding the endwise movement of this shaft 2, the worm issplined on the shaft 2, as previously stated, and it is held immovablyin an endwise direction by a yoke 11 which is supported in fixedposition by a post or standard'12. By this construction, the worm 7 willmaintain a driving connect-ion with the shaft 2 but the latter can shiftaxially or endwise within the worm, the worm, however, being heldimmovably in an endwise or axial direction, and hence it will maintain acorrect operative relation with the worm wheel 10 fixed on the shaft 8.The driving pulley 3 for the shaft 2 may be splined thereon, as shown,so that this pulley may remain in alinement with its driving belt andpulley, or any other suitable means may be provided for driving theendwise shiftable shaft 2. The shaft 8 drives a pair of eccentrics 13which are fixed thereon in the same anular relation and the rods 14,which are criven by these eccentrics, are operatively connected to theopposite ends of a sleeve 15, through which a tool driving bar 16reciprocates. The sleeve 15 and the tool driving bar 16, therein are,when the machine is correctly adjusted, in exact parallelism with theshaft 8, and to enable this adjustment to be obtained or the parts to bere-adjusted, if necessary, the eccentric rods 14 may be constructed oftelescopic or otherwise adjustable sections which maybe secured inproperly adjusted relation by the set screws 17.

The tool driving bar 16 receives a gradual lateral movement through theaction of the eccentrics 13, while this tool driving bar is makingendwise reciprocatory strokes, these reciprocatory strokes beingobtained, in the construction shown, from the crank 5, the pin 6 ofwhich is operatively connected to the bar 16 by the connecting rod 18.The tool driving bar 16 during its lateral movements, under theaction ofthe eccentrics 13, maintains its operative relation with the crank 5which reciprocates this bar, this be ing permitted by the endwise travelof the shaft 2 in its bearings and the splined connection of the wormwheel 7 and, if necessary. the driving pulley 3, with the shaft 2. Thetool drivingbar 16 is accurately guided during its lateral movement, sothat it will move in a true rectilinear direction. For this purpose, theends of the sleeve 15 in which the bar 16 is mounted is provided withguides 19 which are fixed on the base and closely fit the ends of thesleeve 15, which latter acts as a cross head, it thus guiding the tooldriving bar 16 vertically during its lateral shifting movements, andthese guides also support the tool driving bar so that its endwisereciprocatory movements, under the action of the crank, will be in atrue rectilinear direction. t

The tool holder is mounted on the tool driving bar 16, the latter beingpreferably formed with a squared or other angular portion 20 to fitsnugly into a socket 21 formed on the member 22 of the tool holder, andimmovably secured by a set screw 23. The tool holder comprises generallyrelatively movable members, one of which (the member 22 in the presentinstance) is secured to the tool driving bar 16, and the other member 24of which carries the operating tool.

Preferably and as shown, the member 22 of r the tool holder ischannelled or grooved at its opposite sides, as at 25,.to closely butslidingly receive the arms 26 of the tool holder member 24, the latterbeing substantially yoke-shape in form to enable its arms 26 to straddlethe member 22. A roller 27 the purpose of which will be hereinafter'described, is journalled between the arms 26 of the tool holder member24, it being mounted on a shaft 28, the ends of which may be secured inthe arms 26. The member 22 is slotted at its opposite sides, as at 29,to permit the roller shaft 28 to extend through and to shift verticallyin this member of the tool holder, and the latter is also formed with aslot 30 which is transverse to'the slots 29 and serves to accommodatethe roller 27, which latter is movable vertically in this slot duringrelative vertical movements between the tool holder members 22 and '24,The lower ends of the slots 29 are preferably closed, as shown, toprevent detachment of the member 24 from the member 22, unless theroller shaft 28 is removed, accidental detachment of the parts of thetool holderbeing thus avoided. A spring 31 is provided which acts toextend or project the member 24 downwardly or away from the member 22,this spring being shown as bearing on a cross piece 32 which isdetachably fitted across the tops of the arms 26 of the tool holdermember 24.

The tool, which may be in the nature of a file where laps, such as thoseusually composed of metal are to be trued or re-trued, has a universalconnection with the tool holder, whereby the surface of the tool isenabled to maintain a position at a normal to the surface undergoingtruing, although the toolwill be caused to shift in the appropriatedirections relatively to the lap to enable the surface thereof to beproperly trued. Preferably and as shown, the tool, which may be in theform of a flexible file 33 which is sprung or held in proper form by atool socket 34. is connected to the tool holder by fitting the socket 34detachably into a grip 35, a key 36 adapted to pass through registeringholes 37 and 38 in the members 34 and 35 being suitable for adjustablyholding these parts in proper relation. The grip 35 is formed with apair of ears 39 in which a pair of pivot screws 40 are fitted and thesepivot screws fit into recesses 41 in the opposite sides of-a block 42and midway of its length. The lower end of the tool holder member 24 isalso formed with a pair of downwardly projecting ears in which arefitted a pair of pivot screws 44, and the inner ends of these pivotscrews engage in recesses 45 in the respective ends of the block 42. Bythis, or an equivalent construction, the tool is so connected to thetool holder that it may maintain a position at a normal to the surfaceof the lap undergoing truing, with respect to all meridians of suchsurface.

The lap, one of which is shown in .position and designated X in Figure4, is mounted on a suitable lap holder 46. This lap holder may consistof a stud having a key 47 to fit into the key-way in the shank of thelap and thus insure correct positioning of the lap thereon. A spring 48is also provided which acts to force the lap upwardly or in a directiontoward the tool and in opposition to the action of the spring 31 whichforces the tool downwardly or against the surface of the lap.

It is to be understood that a number of tool holders 34 will be providedhaving files or tool surfaces of different radii corresponding with theradii to be given the laps on one meridian, it being merely necessary toplace a tool in the grip 35, the surface of which conforms with thesurface on one meridian of the lap to be treated. If the lap is to havea plane or rectilinear surface on one T meridian, as is the case withlaps used for grinding cylinder lenses, thefile or toolselectedw'ilLbe-straight, whereas, if the lap ".i's't'o have a convexcurvature of-a given radine on such fm'eridian, a '"w'ill be usedhavinga corresponding radius, q'anu'ir the lap is to be given a concavecurva concave tool 33 ture on such meridian of a given radius, the

tool selected will be convex and willhave a corresponding radius. In anycase, it will a be understood that the length "of the file or "munThe'spri'ng48 during the trump. ac-

" tion 'presses the lap upwardly" and thus maintains the requisitepressurebetween it and the tool. The path of movement of the,

" file or'toolv in a direction transverse to its length isggove'r'nedaccording to the; curva ture'to'be given the lap on' its other meridjan; or itsmeridian at right angles to the "meridian first mentionedan dwhich is g'ovcrned by the shape or curvature of the file or tool. Thepath of the tool in this latter or transverse direction is governed bythe relative vertical movements taking place between the tool holdersections 22 and 24, as controlled by a template, one of these templatesbeing provided for each lap curvature to be produced. Preferably and asshown in the present instance, a carriage 49 is provided to receive andsupport the template 50 in proper position, the carriage being mountedor supported to travel in a path in parallelism with the longitudinalreciprocations of the tool driving bar 16, the carriage in theconstruction shown being mounted on a. pair of rails 51, which lattermaybe suitably mounted or supported on the bed or table 1. The endmembers of the carriage may be formed with recesses 52 to removablyreceive and hold the respective ends of the template and the'sidemembers 53 of the carriage lie in close contact with the opposite sidesof the member 24 of the tool holder, so that the carriage willreciprocate in exact synchronism with the reciprocating movements of thetool driving bar, although the tool holder member 24 may move verticallybetween the side vmembers 53 of the carriage,-as controlled by thetemplate during the lateral movement of the tool driving bar under theaction of the eccentrics. The roller 27 of the tool holder bears on thetemplate mounted in the carriage and the roller is held in contact withthe template by I the action of the spring 31. It will be understoodthat any template appropriate to the nature and radius of the curvatureof the lap to betreated can be interchangeably mounted in the carriage49. i 7

, Theoperation of the machine to true or retrue the surface of a lap issubstantially as follows: A. file or tool33 is placedl in the toolsocket 34 which is straight when the surface, of the latter is to beplane or recti linear on one meridan, or is concave or convex on theproper radius when the surface 'of the lapis to be convex or concave onsuch meridian, and a template. 50 is mounted in the carriage which has aconvex or concave curvature of a radius correspond ing to the radius ofthe lapfo'n a meridian at right 'angles to the meridian first mentioned. The lapf i's mounted onthelap 'holder, as showiiinFigure 4fandwith the 'fil'e or tool incon'tactw th the lap and maintainedunder'appropriate pressure, due to the opposing forces of the springs 31and 48, the machine may bestarte'd intooperation, this involvingconcurrent rotation of the shafts, 2"and 8. The shaft 2 reciprocates thetool. driving bar 16 through the action of the cranl rlfi. and the fileor tool is thereby caused to reciprocate longitudinallyback and forthacross the face ofthelap, theluniversalcon;

'nectio'n between the tool'and "tool holder eniii going truing orre-trueing. Preferably, the

gearing or driving connection betweenthe shafts 2 and 8 is such thatthis gradual 3 transverse movement of the tool will occur at eachlongitudinal stroke of the tool, the eccentrics 13 which cause thelateral movement of the tool making one revolution to say longitudinalstrokes of the tool. This operation continues until the face of the laphas been completely trued, the range of transverse movement of the toolbeing suflicient to cover the entire face of the lap and the curvatureof the face of the lap in the direction transverse to the length of thefile or tool is an exact reproduction of the curvature of the templateused, the shape or curvature of the face of the lap on its otherdiameter being made to agree exactly with the shape or curvature of thefile or tool used. Ordinarily, spherical surfaces are produced by usinga file and template of the same curvature, the radius of which agresswith that of the surface to be trued or produced; toric surfaces areproduced by using a file or tool having a radius of curvature conformingwith that of the toric surface on one meridian and a template hav ing aradius of curvature conforming with that of the surface on its othermeridian, and cylinder surfaces are produced by using a straight file ortool and a template having a radius of curvature conforming with that ofthe cylinder surface to be produced. The machine, therefore, is capableof being easily and quickly adapted to true or re-true all of the kindsand degrees of surfaces commonly used for laps, such as those employedin grinding lenses and especially ophthalmic lenses.

We claim as our invention l. A machine for truing lensgrinding lapscomprising. in combination, a lap-support, means for reciprocating atool across the face of a lap on said support, said tool being shaped toconform with the shape to be given the face of the lap on one diameterthereof, means for moving the tool in a direction transverse to itsdirection of reciprocation, and means governing the path of the lattermovement of the tool in conformity with the curvature I to be given theface of the lap on a diameter laps comprising, in combination, alap-slip port, means for reciproating a tool across the face of a lap onsaid support, means for moving the tool in a direction transverse to thedirection of said reciprocating movement, and a templatemounted toreciprocate in unison with said tool and operativefto govern the path ofthe tool during said transverse movement and thereby determine the shapeof the faceof the lap on a corresponding diameter. 7

3. A machine for truing lens-grinding laps comprising, in combination, alap-support, means for guiding a tool to reciprocate in one directionacross the face of a'lap on said support, and means for concurrentlyguiding the tool to move in a path transverse to said reciprocatorymovement and in conformity with the curvature to be given the face ofthe lap in such direction. 4. A machine for truing lens-grinding lapscomprising, in combination, a lap-support, means for reciprocatinga-tool' crosswise on the face of a lap on said support, means for movingthe tool longitudinally oi the face of the lap, and a template having ashape conforming with the shape to be given the face of the lap on itslongitudinal dimension and cooperativewith the tool during its crosswiseand longitudinal movements to govern the path of its lognitudinalmovement.

5. A machine for truing lens-grinding laps comprising, in combination, alaprsupport, means for reciprocating a tool in one direction and forshifting the tool in a direction transverse thereto, means for guidingthe tool to move rectilinearly during its reciprocatory movements, andmeans for guiding the tool to move in a curved path during itsrelatively transverse shifting movement.

6. A machine for truing lens-grinding laps comprising, in combination, alap-support, means for moving a tool in two directions in right-angularrelation with respect to the surface of a lap on said support, means forguiding the tool to move rectilinearly with respect to one of saidmovements, and means for guiding the tool in a curved path with respectto the other of said movements.

7. In a machine for truing lens-grinding laps comprising, incombination, a lap-support, a tool holder embodying a tool member and anactuating member, said members being relatively movable in directionstoward and for shifting said member in a relatively V transversedirection, a template. carriage movable in synchronism with the reciprocatory strokes of the tool holder, and a template on said carriagemember of the.

tool holder to govern the path of the tool during its relativelytransverse shifting movements.

8. In a machine for truing lens-grinding laps comprising, incombination, a lap-support, a tool holder embodying a tool-carryingmember having a universal joint for connecting a tool thereto, and anactuating member, said members being relatively movable in a directiontoward and from the face of a lap on said support, means forreciproeating said actuating member in one direction and for shiftingsaid member in a rela tively transverse direction, a carriage movable insynchronism and parallelism with the reciprocatory movements of saidactuating member and adapted to hold a template, and means on said toolcarrying member cooperative with the template to guide the tool in anarcuate path with respect to said relatively transverse shiftingmovement of the tool.

9. A machine for truing lens-grinding laps comprising, in combination, alap support, a tool holder embodying a tool actuating member and a toolcarrying member, said members being movable relatively to each other indirections toward and from the face of a lap on said support, means forreciprocating said actuating member rectilinearly, means forconcurrently shifting the actuating member in a relatively transversedirection, a carriage reciprocable in synchronism and parallelism withsaid actuating member and adapted to hold a template, means carried bysaid tool holding member and cooperative with the template to guide thetool with respect to its relatively transverse movement, means acting onthe tool carrying member to maintain it in operative relation with thetemplate, and means associated with the lap-support for maintaining thelap in working relation with the tool.

10. A machine for truing lens-grinding laps comprising, in combination,means for yieldingly supporting a lap, means for concurrentlyreciprocating a tool in one direc tion and shifting it in a relativelytransverse direction across the face of a lap on said support, means foryieldingly forcing the tool toward the face of the lap, and means forguiding the tool in a curved path with respect to its relativelytransverse shifting movement.

In testimony whereof we have hereunto set our hands in presence of twosubscribing witnesses.

J OHN J. GUILFOYLE. FREDERICK W. WILKES. BENJAMIN E. BRIERTON.Witnesses:

B. FRANK Yon, F. J. BIRKLEY.

